What application(s) are clustered on those servers? You may run into problems with seeing the shared storage after the P2V.
I would break the cluster and ensure that the application is still functioning at the Windows level before trying to P2V it. I think if you just try to P2V it before making any changes to cluster configuration itself you're headed for problems.
Matt | http://www.thelowercasew.com | @mattliebowitz